Initial tests show deadly ricin poison in letter to Obama

WASHINGTON (USA TODAY) -- The U.S. Secret Service is investigating a letter containing a
"suspicious substance" that was addressed to President Obama, the agency
confirmed on Wednesday, and at least three U.S. senators also reported
receiving suspicious mail.

FBI spokesman Paul Beeson said the letter to Obama tested positive for the poisonous ricin. The letter is undergoing further testing because preliminary field tests can be unreliable, creating false positives.

The
letter was sent to Obama on Tuesday,and was intercepted at the White
House mail screening facility, according to Secret Service spokesman
Brian Leary.

The White House mail screening facility is a remote facility, not located near the White House complex, Leary said.

The
revelation of the suspicious letter to Obama comes less than 24 hours
after U.S. Capitol Police confirmed it was investigating a letter
addressed to Sen. Roger Wicker, R-Miss., that tested positive for the poison ricin in a preliminary examination.

Obama was briefed on the suspicious letters on Tuesday night and
again on Wednesday morning, said White House Press Secretary Jay Carney.

The
FBI says there is no indication that the suspicious letters are
connected to this week's double bombing in Boston. Carney cautioned that
Americans shouldn't jump to any conclusions.

"Before we speculate or make connections that we don't know...we need to get the facts," Carney said.

Another
suspicious package was received Wednesday morning at the Washington
offices of Sen. Richard Shelby, R-Ala., according to Shelby's spokesman
Jonathan Graffeo. He said the package is being investigated by Capitol
Police and it was not known if it was similar to the ones addressed to
Obama and Wicker.

Sen. Carl Levin, D-Mich., issued a statement
saying that a suspicious letter also was received Wednesday morning at
his Saginaw, Mich., field office. He said the staffer who received the
letter did not open it and turned it over to authorities, who are
investigating.

"We do not know yet if the mail presented a threat," Levin said.

The
letter to Wicker, which was intercepted at an off-site Capitol mail
facility, was found to contain a "white granular substance'' and was
quarantined before a preliminary test indicated the substance was ricin,
the statement said.

"The material is is being forwarded to an
accredited laboratory for further analysis," according to the statement
authorized by U.S. Capitol Police Chief Kim Dine.

Bresson, the FBI
spokesman, said that filters at one of the remote facilities used to
screen official mail also tested positive for ricin this morning.

Anytime
suspicious powder is located in a mail facility, field tests are
conducted, Bresson said, but those tests can produce inconsistent
results.

If the tests indicate the possibility of a biological
agent, the material is sent to an accredited laboratory for further
analysis, and only those tests can confirm the presence of a biological
agent. Those tests are currently being conducted and generally take from
24 to 48 hours, Bresson said.

The U.S. Capitol Police alerted
congressional staff just after noon that they were investigating a
suspicious package in the atrium of the Hart Senate Office Building, as
well as suspicious envelopes received in upstairs offices of both the
Hart building and the nearby Senate Office Building. The message advised
staff that they were not required to stay in their office, but to avoid
the areas where the suspicious packages were being investigated.

An
announcement in the buildings just before 1 p.m. said that test results
on the packages were negative and closed off areas had reopened.

Scott
Ongill, a Senate staffer, said such alerts are not unusual. "There is a
couple, three (alerts) a week around the Capitol campus. It's not that
uncommon an occurrence. They're doing due diligence." He said they
usually end up being tourists who left something.

Kathy Windsor of
Lebanon, Mo. , was in Washington, D.C., to lobby on a bill with
Missouri lawmakers including Sen. Claire McCaskill. "They will not let
us in the building," she said. She was told Hart was closed "until
further notice." "With what's happened this week they have to take
everything seriously," Windsor said.